If Sebastian Coe wasn't entirely sure about what he's letting himself in for by going forward as the new leader of world athletics, then he is now.

Even for a sport with a lot of dirty secrets already exposed, few people expected the latest of those to hurt quite like this: three Olympic Games, six World Athletics Championships, and nothing it seems but blood on the tracks.

It follows the revelations over the weekend that as many as one third of the medals won at those championships, from 2001 to 2012, could be tarnished by various blood-doping practices. Worse still, those revelations only concern endurance events, when the dirtiest secrets in athletics have nearly always been in the sprints and throwing events.

Coe is in the final two weeks of his campaign to take over as president of the IAAF, the governing body of world athletics, with that election set for the eve of the 15th World Athletics Championships in Beijing. Coe is the favourite to succeed the 80-year-old Senegalese, Lamine Diack.

According to the allegations made after a joint investigation by German broadcaster ARD/WDR and the Sunday Times, Diack's presidency coincided with a time when the IAAF kept a lid on some 12,000 blood samples from around 5,000 athletes, which contained some worrying and in fact dangerous evidence of blood-doping practices.

Banned

None of this evidence necessarily meant the athletes in question should have been banned; but there was enough evidence to merit further investigation.

Yet Coe is among those to defend the IAAF stance on doping in recent years, and believes the latest allegations will be dealt with accordingly. “In response to media reports, I know that the IAAF takes these allegations extremely seriouslyand it will issue a robust and detailed response to them and continue to work closely, as it has always done, with World Anti-Doping Agency [Wada],” he said.

The IAAF also responded with the following statement: “The IAAF is aware of serious allegations made against the integrity and competence of its anti-doping programme.

"The relevant allegations were broadcast on WDR (ARD) in Germany yesterday and have been repeated in an article in the Sunday Times newspaper. They are largely based on analysis of an IAAF data base of private and confidential medical data which has been obtained without consent. The IAAF is now preparing a detailed response to both media outlets and will reserve the right to take any follow-up action necessary to protect the rights of the IAAF and its athletes."

It is alleged that more than 800 athletes who had provided those blood samples were deemed “highly suggestive” of doping or else “abnormal”.

The data was provided by a whistleblower and then analysed by two leading anti-doping experts, particularly in the field of blood-doping – scientist Robin Parisotto and exercise physiologist Michael Ashenden, both based in Australia. Based on their interpretation of the data, a third of medals won (146 in all, including 55 gold) in endurance events at the Olympics and World Championships between 2001 and 2012 were won by athletes who have recorded suspicious tests – yet none of them were stripped of their medals.

Leaders

This was the news that greeted many of the leaders of world sport currently attending the International Olympic Committee session in Kuala Lumper, including Wada chief executive Craig Reedie.

“These are wild allegations, wide allegations, and we will check them out, and have that done with the commission, as quickly as possible,” said Reedie. “I am very surprised by the numbers from the leak from the IAAF, and I am sure they will want to look at it closely to determine the source. But I stress athletes are innocent until proven guilty.”

A leading British athlete was also linked to seven of their athletes with “suspicious” blood scores, although that athlete wasn’t named for legal reasons.

It was also stated in the Sunday Times report that Britain's Mo Farah and Jamaican sprinter Usain Bolt, who have been the subject of whispering campaigns in recent weeks, were not among the athletes listed, as they effectively emerged as clean, with no abnormal results.